63561205005421 has 2 divisors, whose sum is σ = 63561205005422. Its totient is φ = 63561205005420.

The previous prime is 63561205005413. The next prime is 63561205005491. The reversal of 63561205005421 is 12450050216536.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56407024432521 + 7154180572900 = 7510461^2 + 2674730^2 .

It is a cyclic number.

It is not a de Polignac number, because 63561205005421 - 2³ = 63561205005413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (63561205005491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31780602502710 + 31780602502711.

It is an arithmetic number, because the mean of its divisors is an integer number (31780602502711).

Almost surely, 2^{63561205005421} is an apocalyptic number.

It is an amenable number.

63561205005421 is a deficient number, since it is larger than the sum of its proper divisors (1).

63561205005421 is an equidigital number, since it uses as much as digits as its factorization.

63561205005421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216000, while the sum is 40.

The spelling of 63561205005421 in words is "sixty-three trillion, five hundred sixty-one billion, two hundred five million, five thousand, four hundred twenty-one".